Influence of promoters on the structural and catalytic functionalities of V2O5/Al2O3 catalysts for the ammoxidation of ortho-chlorotoluene

摘要

Mo, W and La promoted V2O5/Al2O3 catalysts were prepared and evaluated for the ammoxidation of 2-chlorotoluene to 2-chlorobenzonitrile. The catalysts were characterized by BET surface area, X-ray diffraction, temperature programmed reduction and temperature programmed desorption of ammonia. The characterization results revealed that the formation of metal vanadates depends on the nature of promoter and its loading. The promotion of metal oxides induces the formation of isolated and polymeric vanadia species. The promoters improve the reducibility of vanadia and total acidity. The catalytic activity of the catalysts varies with the addition of promoters and La promoted catalysts are more active compared to others. The highest activity obtained for the La2O3 promoted V2O5/Al2O3 catalyst is due to the high reducibility of vanadia and total acidity.